The present invention relates to storage racks used in warehousing and more particularly to a storage rack wherein modular pallet carriers convey pallets back or through a storage bay having a multiple pallet depth.
Warehouse storage racks typically comprise a frame structure divided into rows and columns that define storage bays for depositing storage units, commonly pallets, of products to be stored. In order to conserve space in a storage facility, storage bays are sometimes more than one pallet deep. Movable carriers mounted on tracks are sometimes used to permit pallets to be moved to rearward storage locations from a single loading station at the front of the rack system. One such rack system is a “push back system” or “roll back system”, wherein pallets are loaded at a front of the storage bay and pushed rearward by the next pallets as they are loaded on the rack. Then the pallets are unloaded from the front of the storage bay on a last in, first out (LIFO) basis. In another storage rack system, pallets are loaded at one end of the storage bay and pushed through the storage bay and unloaded from the other side of the storage bay. These are known as “flow through systems,” and facilitate first in, first out (FIFO) product flow.
A push back or roll back storage rack system is disclosed in Applicant's U.S. Pat. No. 6,431,378, the disclosure of which is incorporated here by reference. One of the embodiments disclosed in this patent is a modular system wherein modular track sections are mounted in a storage rack and interconnected to provide a push back type of rack (see FIGS. 22-44). The present invention provides an improved modular rack system that is adaptable to either a flow-through system or a push back system.
For purposes of illustration, a flow-through system will be described. The end of the storage bay where goods are loaded on to the rack will be referred to as the front of the rack, whereas the opposite end of the rack where goods are unloaded will be referred to as the rear or back of the rack. Goods moving in a forward direction through the rack are goods moving from the front to the rear of the storage bay.